共查询到20条相似文献，搜索用时 390 毫秒
1.
Lawrence W. C. Lai K. W. Chau S. K. Wong N. Matsuda Frank T. Lorne 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):289-316
ABSTRACT From a transaction cost perspective, this paper shows how the tradition of consuming marine fish by the majority of Hong Kong's Chinese citizens has shaped the means and modes of marketing seafood in Hong Kong. It is argued that consumer preferences stimulate aquaculture as a non-open access measure to bypass state fish marketing regulations. This has resulted in two outcomes. First, the transaction cost savings on metering output quantity and quality under private property have led not only to the collapse of the state monopoly on marine fish marketing, but also to the emergence of the (then new but) currently popular kind of Chinese seafood restaurant in Hong Kong. Second, consumer preferences for variety have shaped the form of coordination between the producer and the consumer. The advantage of market coordination has led to the emergence of a system of wholesaling and retailing rather than vertical integration. Issues concerning the emergence of Hong Kong as a regional live marine fish production and trading centre are discussed in terms of the contribution of local mariculture to sustainable development. 相似文献
2.
Historic and current information on the grouper fishery from Hong Kong and adjacent waters reveals significant changes in species composition and fish sizes over the past 50 years in this important Asian centre for seafood consumption. Once dominant, large groupers are now rare and small species and sizes prevail in the present‐day fishery. Juveniles comprise over 80% of marketed fish by number among the most commonly retailed groupers, and reproductive‐sized fish are absent among larger species. Current fishery practices and the lack of management in Hong Kong and adjacent waters pose a significant threat to large species with limited geographic distribution such as Epinephelus akaara and Epinephelus bruneus, both now listed as threatened by the IUCN. The heavy reliance on juveniles, not only for groupers, but for an increasing diversity of desired fishes within Asia, potentially reduces stock spawning potential. The ‘shrinking baseline’ in terms of a progressive reduction in fish sizes being marketed in the region can seriously undermine fishery sustainability and recoverability of depleted fish stocks. Fishing pressure on groupers and other valuable food fishes within the Asia‐Pacific is intensifying, the declining long‐term trend of grouper landings in Hong Kong and the increasing focus on juveniles for immediate sale or for mariculture ‘grow‐out’ signal a worrying direction for regional fisheries. Moreover, the common appearance of small groupers for sale will influence public perception regarding what are ‘normal‐sized’ fish. Management attention is needed if these fisheries are to remain viable. 相似文献
3.
A market survey and review of government statistics were carried out to establish imports and exports of marine ornamental fishes into and out of Hong Kong, and to examine the local trade in terms of volume, value and species composition. Official government import figures for marine aquarium fishes were available from 1984 to 1991 and from 1997 and 1998. When compared with net imports, export and re-export volumes over the 15-year period were small, indicating that most imports entered the local market, or were exported unrecorded. The market survey of marine aquarium shops in Hong Kong was carried out between August 1996 and January 1997. From this survey, an annual estimate of 957,563 coral reef fish was calculated for the local trade, valued at HK$57,453,780, with a mean retail price of HK$60 per fish. These figures account for an estimated 2–3% of the global value and volume of marine aquarium fish trade, according to 1992 figures and, compared with government figures, indicate that official declarations of imports are underreported by at least 2–3 fold. A total of 342 marine aquarium fish species, from 49 families, were recorded with about 60% belonging to the families Labridae, Chaetodontidae, Pomacanthidae and Pomacentridae. It was estimated that a large proportion of the trade was in juvenile fishes and almost all fish were less than 10cm in standard length. It was common to see fishes in poor condition, species hard to maintain in captivity, or those listed for conservation concern, on sale. There are no regulations for local traders of live marine fishes other than those relating to either protected species or animal welfare. Licensing of traders in marine fishes could be introduced under existing Hong Kong legislation if fishes were to be re-classified as animals. This is strongly recommended as a step towards regulating and managing the trade in Hong Kong. 相似文献
4.
A survey of integrated agriculture–aquaculture systems (IAAS) was carried out in four different agroecologies, an irrigated and three rainfed agroecologies (drought‐prone, rainfed lowland and rolling land), in Northeast region of Thailand, of tropical wet:dry climate. Fish culture system of IAAS varied with agroecology but not with the length of farmers' experience in IAAS farming. The size of pond holdings in the rainfed lowland agroecology was estimated to be significantly smaller (P≤0.05) than in the three other agroecologies. The highest average extrapolated gross fish yield of 2.3 tonnes ha?1 was recorded in the irrigated agroecology and this was significantly higher (P≤0.01) than in the three rainfed agroecologies: drought‐prone (1.1 tonnes ha?1), rainfed lowland (0.5 tonnes ha?1) and rolling land (0.4 tonnes ha?1). Higher fish yield in the irrigated agroecology was associated with longer stocking period and higher amount of pond inputs. Average income of IAAS households from fish also varied across agroecology in a fashion that was noted for yields. However, the farm pond played a pivotal role in the diversification of the farming system in rainfed agroecologies, as it was essentially the only source of water supply for fruit and vegetables production. While fish culture in all agroecologies was a low‐input system, intensification through fertilization of ponds with chemical fertilizers can be envisaged to increase fish production in IAAS in Northeast Thailand. 相似文献
5.
P. A. Larkin 《Ecology of Freshwater Fish》1992,1(1):1-4
Abstract– Projected world population increases imply demand for an increase of 60 million tonnes on the present world fish production of 100 million tonnes. Capture fisheries are unlikely to yield more because many stocks are already overexploited, there are few remaining unexploited and management shows few signs of redressing problems. Aquaculture is a possible source of the required production, given maintenance of current rates of increase. If this potential is to be realized, the importance of maintaining the quality of freshwater, brackish and coastal marine environments can scarcely be overstated. In a world of rapid change, there is an urgent need for research at all levels of biological and social organization that relate to the ecology of freshwater fish. At the organismic level, genetics, migratory behaviour and physiological ecology will be emphasized. Population genetics research is needed to enlighten controversies concerning the impact of cultural practices and the effects of harvesting natural populations. Greater attention will be given to interactions between species, including fish and their parasites, and the dynamics of multispecies interactions in pond culture and in capture fisheries. Issues of multiple uses of water resources will force research on freshwater fish ecology into broader contexts. The march of discovery in all branches of science will have major implications for freshwater fisheries research. The next few decades will be demanding of the creative energies of young researchers. 相似文献
6.
Yukari Asano Ken-ichi Hayashizaki Hiroki Eda Thongkhoune Khonglaliang Hisashi Kurokura 《Fisheries Science》2010,76(5):811-817
Nile tilapia, Oreochromis niloticus, is one of the most popular freshwater aquaculture species in developing countries. Although formulated feed provides higher
fish yield, it is expensive. Therefore, fertilizer-based fish culture using natural food sources is generally implemented
in developing countries. The aim of this study was to identify the major natural foods contributing to tilapia growth in fertilizer-based
fish ponds. The stomach contents of tilapia in a fertilizer-based fish pond in Lao PDR were analyzed to estimate their feeding
behaviors; stable isotope ratios of carbon and nitrogen in the potential food organisms and suspended solids were measured
and compared with the ratios in the fish muscle tissues. Further, the feed efficiency of chironomid larvae was compared with
that of chlorella and formulated feed in a laboratory feeding experiment. Consequently, chironomid larvae were identified
as the main contributors to tilapia growth in the fertilizer-based fish pond. In conclusion, benthic larvae of insects belonging
to the family Chironomidae are confirmed to be a natural food source for tilapia in the fertilizer-based fish pond. 相似文献
7.
在盐碱地一个面积为2871m^2的鱼池中，配置4个网箱．分别放养罗非鱼、淡水白鲳和鲤，箱外放养鲢、草鱼和鲤。试验结果：罗非鱼箱(20m^2)出鱼525kg．平均单产26．3kg／m^2,淡水白鲳箱(12m^2)出鱼400kg,平均单产33.3kg／m^2,鲤鱼箱两个(各12m^2)分别出鱼488．5kg和522kg，平均单产为40．7kg／m^2和43．5kg／m^2。箱外出鲢516kg,草鱼130kg，鲤1125kg。总计全池出鱼3706．5kg，亩产鱼862kg，每亩纯盈利2173．85元。试验证明：池塘配置网箱养鱼．可同池主养几种鱼，起捕容易，管理方便。 相似文献
8.
自20世纪40年代,后海湾就成为香港的池塘养殖中心。虽然在过去数十年间池塘养殖业的管理效率及水产品质量得到了不断提高及改良,但仍然未达到现代化的生产水平。1990年代中期,由于多种因素的共同作用,养殖业逐渐衰落。与此同时,香港政府指定后海湾一带的商业鱼塘为"资源合理利用区",肯定了鱼塘对湿地物种养护及养殖户经济收益的重要性。有见及此,世界自然基金会香港分会通过共同管理模式与养殖户合作,借助"绿色养殖",在社会、经济、生态三方面实现高度协调,尝试把后海湾逐渐衰落的池塘养殖业发展成为可持续发展工业。 相似文献
9.
This article records the trade practice and culture cycle of Ophiocephalus maculatus (snakeheads) as adopted by a fish farm at Ngau Tam Mei, the New Territories, Hong Kong. This farm is one of the few remaining local enterprises that have the skills to spawn this labyrinth fish. Documentation is timely not only because there has been great demand for the transfer of culture technology (spawning) to China, but also because the species may become extinct with the demise of the culture business through urbanization. The discussion throws light on the effectiveness and limitations of the institutions of private rights as a means of conserving common resources. 相似文献
10.
A Survey of Water Quality Characteristics of Effluent from Hawaiian Aquaculture Facilities 总被引：2，自引：0，他引：2
David A. Ziemann William A. Walsh Eva G. Saphore Kim Fulton-Bennett 《Journal of the World Aquaculture Society》1992,23(3):180-191
Ten water quality parameters were measured in influent and effluent water at 11 aquaculture facilities in Hawaii. The data were grouped into four categories based on the types of organisms cultured: freshwater fish, freshwater prawn, marine fish, and marine shrimp. Within each category, concentrations of most parameters were lognormally distributed and spanned one to two orders of magnitude. Geometric mean concentrations of suspended materials, total nitrogen, total phosphorus, and pigments were highest in effluent from freshwater prawn ponds and lowest in marine fish pond effluent. Nitrate/Nitrite and total ammonia concentrations were higher in fish pond effluent than in crustacean pond effluent. Parameter concentrations were generally higher in effluent than in influent water, with freshwater fish and prawn ponds exhibiting the greatest increases in suspended materials and pigments. In contrast, nitrate/nitrite concentrations were lower in effluent than in influent waters. These data provide a basis for analyzing the environmental impacts of warm-water aquaculture effluent discharges. 相似文献
11.
Shelley Clarke 《Fish and Fisheries》2004,5(1):53-74
This study investigates the dried seafood trade, centred in Chinese markets, in order to better understand the pressures its demand exerts on global marine resource stocks. Using Hong Kong, the region's largest entrepôt, as a focal point, the trade in shark fins, abalone, bêche‐de‐mer and dried fish is characterized in terms of product history, volume, source fisheries and species composition. Trends identified in the Hong Kong market are interpreted in the context of the larger Chinese market. Shark fin imports grew 6% per year between 1991 and 2000, most likely because of market expansion in Mainland China, posing increasingly greater pressures on global shark resources. In contrast, the quantities of dried abalone traded through Hong Kong remained steady, but inferences based on this trend are discouraged by suggestions of increasing preferences for fresh product forms and growing domestic production in Mainland China. Hong Kong's imports of dried bêche‐de‐mer (sea cucumber) have decreased, while the percentage of imports re‐exported has remained steady, suggesting that Hong Kong continues as an entrepôt for Mainland China despite declining domestic consumption. Few conclusions can be drawn regarding dried fish products, including whole fish and fish maws, because of a lack of product differentiation in customs data, but a market survey was conducted to provide information on species composition. Comparison of Hong Kong dried seafood trade statistics to those of other key trading partners indicates that, in general, Hong Kong's duty‐free status appears to encourage more accurate reporting of traded quantities. Under‐reporting biases ranged from 24 to 49% for shark fin and bêche‐de‐mer, respectively. Comparison to United Nations (UN) Food and Agriculture Organization (FAO) databases indicates additional under‐reporting for shark fin such that an alternative minimum estimate of world trade is at least twice the FAO estimates in 1998–2000. The results of a survey of Hong Kong traders provide insight into their attitudes toward harvest, economic and regulatory factors, and suggest that conservation efforts are unlikely to emerge from, or be actively supported by, dried seafood trade organizations. The market's apparent sensitivity to economic sentiment, however, reveals an opportunity for consumer education to play a role in shaping future market growth and resource conservation. Recommendations are provided for improving trade statistics and for developing better analytical techniques to complement traditional methods for monitoring the exploitation and management of fisheries resources. 相似文献
12.
13.
池塘养鱼生产经营效益关系到产业自身的巩固和发展,作者经过多年的生产,科研和调查研究,并在１９９－１９９３年以上海市淀山湖联营养殖场为试点,探索池塘养鱼高效益管理模式,归纳为“一个目标,二个保证,三种动力”的“１－２－３管理模式”。具体实施后,淀山湖联营养殖场１９９３年获池塘养鱼每公顷净产１１５６５公斤,每个职工平均产值达４２３７５．３２元,实现了高产,优质,高效益的管理目标。 相似文献
14.
《Journal Of Applied Aquaculture》2013,25(1-2):145-178
ABSTRACT Low survival rates during larval stages constitute a major bottleneck in the successful culture of many marine and some freshwater fish. The availability of live food is recognized as a critical factor influencing larval survival. Live food is still superior to the best larval diets in terms of larval survival and growth. This paper reviews important ecological and ethological aspects of feeding, from hatching tothe weaning stage, and relates them to problems in larval culture. In general, freshwater fish larvae are easier to raise than marine fish larvae, because at hatching they are larger and endowed with more yolk reserves, are less sensitive to starvation, and canbe weaned to artificial diets sooner. The feeding behavior of the larvae can be analyzed in terms of the sequential components of predation: search, encounter, pursuit, attack, capture, and ingestion. The searching efficiency and encounter rates of the visual predator are influenced by prey parameters such as body size, conspicuousness, and evasiveness. Turbidity of the water and light intensity also affect prey detection. To changing prey densities, the larvae show typical Type II functional responses, which are influenced by prey handling time, which in turn is largely a function of prey size. Knowledge of larval functional responses is helpful in providing the right concentrations oflive food for larval culture. The larvae are initially gape-limited and exhibit prey size selectivity but gradually widen their prey size range as they grow. An aquacultural application of this is the commonly employed feeding protocol, prey size sequencing, in which progressively larger live food items are offered as the larvae grow. A thorough knowledge of the feeding behavior is also essential in the formulation of acceptable larval diets. 相似文献
15.
The long-term sustainability of the marine ornamental industry is being threatened by environmental pressures that are severely degrading the health of coral reef ecosystems. There is now a compelling need to practice resource conservation through the development of 'reef friendly' aquaculture technologies as an alternative to wild collection practices and to restore degraded wild populations. The commercial culture of marine ornamental finfish is very much in its infancy, but advances can be made more rapidly using insights from years of research and development with marine foodfish species. Many of the bottlenecks and constraints to developing marine ornamental fish culture are those now being addressed with the more challenging species of foodfish being attempted. The two key bottlenecks that currently limit expansion of the marine ornamental industry are the control of captive maturation and spawning and the identification of appropriate first-feed items for marine ornamental fish larvae. This paper highlights basic principles and recent achievements in marine foodfish culture that might be applicable to rapid development of controlled reproduction and propagation techniques for marine ornamental finfish. 相似文献
17.
Paiboon Bunlipatanon Narin Songseechan Hassanai Kongkeo Nigel W Abery Sena S De Silva 《Aquaculture Research》2014,45(3):373-388
Trash fish/low valued fish is still the most commonly used feed in marine cage culture in Asia. Use of trash fish is controversial with regard to the sustainability of the farming practices, and related issues on environmental degradation. In this study, the results of farm based trials on Asian seabass (Lates calcarifer) and tiger grouper (Epinephelus fuscoguttatus) to evaluate the efficacies of the use of commercial pellet feed in comparison to trash fish/low valued fish in marine cages in Thailand are presented. In spite of the variations observed in each of the farm sites, the results indicate that the overall growth performances and fish survival rates between the two feed types were similar, for both species. However, better cost‐benefit and resource use were recorded for fish reared on trash fish/low valued fish. No significant differences were observed in water quality parameters, dissolved oxygen, transparency and ammonia, between sites where pellet or trash fish were used, inside and outside the cages and for both species. The results of the present study are discussed in the light of the current controversies on the use of trash fish/low valued fish in marine cage culture. 相似文献
18.
《Journal Of Applied Aquaculture》2013,25(3-4):283-316
ABSTRACT India is a very populous country with more than one billion people. In order to provide food for this growing population, serious environmental problems may result. Despite many benefits from the green, blue, and silver revolutions adopted in India, there has been much concern resulting from intensive agricultural practices that led to environmental problems in both terrestrial and aquatic ecosystems. Increasing demand for aquatic resources also caused inland fisheries to decrease over the past few decades. The location of aquaculture projects, landscape destruction, soil and water pollution by pond effluents, over-exploitation of important fish stocks, depletion in biodiversity, conflicts over agriculture and aquaculture among various stakeholder groups over resource and space allocation, and international fish trade controversies have threatened the long-term sustainability of fisheries and aquaculture industries. The subject of sustainable aquaculture has not been adequately projected in terms of current aquaculture practices aimed to boost a rural economy. This review briefly describes the key issues of aquaculture unsustainability in terms of intensive aquaculture, nutrient enrichment syndrome, soil and groundwater salinization, destruction of mangroves, loss of biodiversity, marine pollution and loss of fish stock, use of aquachemicals and therapeutics, hormone residues, etc. The strategies for sustainability have been highlighted with respect to rice-cum-fish culture, carp polyculture, integrated farming with livestock, rural aquaculture, intensification of small farms, wastewater-fed aquaculture, crop rotation, probiotics, feed quality, socioeconomic considerations, environmental regulations and fisheries acts, transboundary aquatic ecosystems, impact of alien species, ethical aspects of intensive aquaculture, responsible fisheries, and environmental impact assessment. A suggested model outlines the feedback mechanisms for achieving long-term sustainability through improved farm management practices, integrated farming, use of selective aquachemicals and probiotics, conservation of natural resources, regulatory mechanism, and policy instruments. 相似文献
19.
鱼类是一个迄今尚未被认知的非常重要的微细碳酸盐沉积物的来源,对海洋固碳有着重要作用,这个发现直接影响到碳汇渔业的内涵.本研究介绍了海洋硬骨鱼类渗透压调节机制及鱼类肠道碳酸盐结晶形成与其肠细胞膜上物质转运之间的关系,着重阐述了鱼类肠道碳酸盐结晶的特征,并论述了通过对特定区域内鱼类生物量和碳酸盐排泄率数据的研究,估计出全球海洋鱼类每年可产生大约1.1亿t的碳酸钙,在海洋总碳酸盐岩泥中占14％以上.研究重点论述了海水鱼类固碳的独特优势潜力,同时,提出为了更好地确定海水鱼类养殖在碳汇渔业中的地位和作用,有必要对主要海水养殖鱼类肠道碳酸结晶物的形成量及其调控机制,碳收支动态模型进行研究,进而合理地估算和测定海水鱼类养殖的碳汇量. 相似文献
20.
Abstract The effects of perch, Perca fluviatilis L., and bronze bream, Abramis brama (L.), predation on the production of insects emerging at the water surface and the autumn biomass of benthic macro-invertebrates were assessed in a series of experimental ponds. The study attempted to discover whether fish affect food availability for diving and dabbling ducks in freshwater habitats. Ten ponds (bisected by fine netting) were used for the study: one was left totally fish-free, whilst one half of each of three groups of three ponds was stocked with either perch, bream or perch plus bream. The relative abundance of emerging insects (mainly Chironomidae) was significantly reduced in two perch ponds, two perch + bream ponds and two bream ponds. The autumn standing crops of benthic macroinvertebrates were significantly reduced in one perch pond, three bream ponds and one perch plus bream pond. These results support findings of a contemporaneous large bio-manipulation experiment carried out in two adjacent lakes. During the biomanipulation studies, aquatic invertebrate standing stocks greatly increased after the removal of fish and decreased following restocking. 相似文献